source: MondoRescue/branches/3.0/mindi-busybox/miscutils/conspy.c@ 2899

Last change on this file since 2899 was 2725, checked in by Bruno Cornec, 13 years ago
  • Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3
  • Property svn:eol-style set to native
File size: 13.3 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * A text-mode VNC like program for Linux virtual terminals.
4 *
5 * pascal.bellard@ads-lu.com
6 *
7 * Based on Russell Stuart's conspy.c
8 * http://ace-host.stuart.id.au/russell/files/conspy.c
9 *
10 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
11 */
12
13//applet:IF_CONSPY(APPLET(conspy, _BB_DIR_BIN, _BB_SUID_DROP))
14
15//kbuild:lib-$(CONFIG_CONSPY) += conspy.o
16
17//config:config CONSPY
18//config: bool "conspy"
19//config: default n
20//config: depends on PLATFORM_LINUX
21//config: help
22//config: A text-mode VNC like program for Linux virtual terminals.
23//config: example: conspy NUM shared access to console num
24//config: or conspy -nd NUM screenshot of console num
25//config: or conspy -cs NUM poor man's GNU screen like
26
27//usage:#define conspy_trivial_usage
28//usage: "[-vcsndf] [-x COL] [-y LINE] [CONSOLE_NO]"
29//usage:#define conspy_full_usage "\n\n"
30//usage: "A text-mode VNC like program for Linux virtual consoles."
31//usage: "\nTo exit, quickly press ESC 3 times."
32//usage: "\n"
33//usage: "\nOptions:"
34//usage: "\n -v Don't send keystrokes to the console"
35//usage: "\n -c Create missing devices in /dev"
36//usage: "\n -s Open a SHELL session"
37//usage: "\n -n Black & white"
38//usage: "\n -d Dump console to stdout"
39//usage: "\n -f Follow cursor"
40//usage: "\n -x COL Starting column"
41//usage: "\n -y LINE Starting line"
42
43#include "libbb.h"
44#include <sys/kd.h>
45
46
47#define ESC "\033"
48
49struct screen_info {
50 unsigned char lines, cols, cursor_x, cursor_y;
51};
52
53#define CHAR(x) (*(uint8_t*)(x))
54#define ATTR(x) (((uint8_t*)(x))[1])
55#define NEXT(x) ((x) += 2)
56#define DATA(x) (*(uint16_t*)(x))
57
58struct globals {
59 char* data;
60 int size;
61 int x, y;
62 int kbd_fd;
63 int ioerror_count;
64 int key_count;
65 int escape_count;
66 int nokeys;
67 int current;
68 int first_line_offset;
69 int last_attr;
70 // cached local tty parameters
71 unsigned width;
72 unsigned height;
73 unsigned col;
74 unsigned line;
75 smallint curoff; // unknown:0 cursor on:-1 cursor off:1
76 char attrbuf[sizeof(ESC"[0;1;5;30;40m")];
77 // remote console
78 struct screen_info remote;
79 // saved local tty terminfo
80 struct termios term_orig;
81 char vcsa_name[sizeof("/dev/vcsaNN")];
82};
83
84#define G (*ptr_to_globals)
85#define INIT_G() do { \
86 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
87 G.attrbuf[0] = '\033'; \
88 G.attrbuf[1] = '['; \
89 G.width = G.height = UINT_MAX; \
90 G.last_attr--; \
91} while (0)
92
93enum {
94 FLAG_v, // view only
95 FLAG_c, // create device if need
96 FLAG_s, // session
97 FLAG_n, // no colors
98 FLAG_d, // dump screen
99 FLAG_f, // follow cursor
100};
101#define FLAG(x) (1 << FLAG_##x)
102#define BW (option_mask32 & FLAG(n))
103
104static void clrscr(void)
105{
106 // Home, clear till end of screen
107 fputs(ESC"[1;1H" ESC"[J", stdout);
108 G.col = G.line = 0;
109}
110
111static void set_cursor(int state)
112{
113 if (G.curoff != state) {
114 G.curoff = state;
115 fputs(ESC"[?25", stdout);
116 bb_putchar("h?l"[1 + state]);
117 }
118}
119
120static void gotoxy(int col, int line)
121{
122 if (G.col != col || G.line != line) {
123 G.col = col;
124 G.line = line;
125 printf(ESC"[%u;%uH", line + 1, col + 1);
126 }
127}
128
129static void cleanup(int code)
130{
131 set_cursor(-1); // cursor on
132 tcsetattr(G.kbd_fd, TCSANOW, &G.term_orig);
133 if (ENABLE_FEATURE_CLEAN_UP) {
134 close(G.kbd_fd);
135 }
136 // Reset attributes
137 if (!BW)
138 fputs(ESC"[0m", stdout);
139 bb_putchar('\n');
140 if (code > 1)
141 kill_myself_with_sig(code);
142 exit(code);
143}
144
145static void screen_read_close(void)
146{
147 unsigned i, j;
148 int vcsa_fd;
149 char *data;
150
151 // Close & re-open vcsa in case they have swapped virtual consoles
152 vcsa_fd = xopen(G.vcsa_name, O_RDONLY);
153 xread(vcsa_fd, &G.remote, 4);
154 i = G.remote.cols * 2;
155 G.first_line_offset = G.y * i;
156 i *= G.remote.lines;
157 if (G.data == NULL) {
158 G.size = i;
159 G.data = xzalloc(2 * i);
160 }
161 else if (G.size != i) {
162 cleanup(1);
163 }
164 data = G.data + G.current;
165 xread(vcsa_fd, data, G.size);
166 close(vcsa_fd);
167 for (i = 0; i < G.remote.lines; i++) {
168 for (j = 0; j < G.remote.cols; j++, NEXT(data)) {
169 unsigned x = j - G.x; // if will catch j < G.x too
170 unsigned y = i - G.y; // if will catch i < G.y too
171
172 if (CHAR(data) < ' ')
173 CHAR(data) = ' ';
174 if (y >= G.height || x >= G.width)
175 DATA(data) = 0;
176 }
177 }
178}
179
180static void screen_char(char *data)
181{
182 if (!BW) {
183 uint8_t attr = ATTR(data);
184 //uint8_t attr = ATTR(data) >> 1; // for framebuffer console
185 uint8_t attr_diff = G.last_attr ^ attr;
186
187 if (attr_diff) {
188// Attribute layout for VGA compatible text videobuffer:
189// blinking text
190// |red bkgd
191// ||green bkgd
192// |||blue bkgd
193// vvvv
194// 00000000 <- lsb bit on the right
195// bold text / text 8th bit
196// red text
197// green text
198// blue text
199// TODO: apparently framebuffer-based console uses different layout
200// (bug? attempt to get 8th text bit in better position?)
201// red bkgd
202// |green bkgd
203// ||blue bkgd
204// vvv
205// 00000000 <- lsb bit on the right
206// bold text
207// red text
208// green text
209// blue text
210// text 8th bit
211 // converting RGB color bit triad to BGR:
212 static const char color[8] = "04261537";
213 const uint8_t fg_mask = 0x07, bold_mask = 0x08;
214 const uint8_t bg_mask = 0x70, blink_mask = 0x80;
215 char *ptr;
216
217 ptr = G.attrbuf + 2; // skip "ESC ["
218
219 // (G.last_attr & ~attr) has 1 only where
220 // G.last_attr has 1 but attr has 0.
221 // Here we check whether we have transition
222 // bold->non-bold or blink->non-blink:
223 if (G.last_attr < 0 // initial value
224 || ((G.last_attr & ~attr) & (bold_mask | blink_mask)) != 0
225 ) {
226 *ptr++ = '0'; // "reset all attrs"
227 *ptr++ = ';';
228 // must set fg & bg, maybe need to set bold or blink:
229 attr_diff = attr | ~(bold_mask | blink_mask);
230 }
231 G.last_attr = attr;
232 if (attr_diff & bold_mask) {
233 *ptr++ = '1';
234 *ptr++ = ';';
235 }
236 if (attr_diff & blink_mask) {
237 *ptr++ = '5';
238 *ptr++ = ';';
239 }
240 if (attr_diff & fg_mask) {
241 *ptr++ = '3';
242 *ptr++ = color[attr & fg_mask];
243 *ptr++ = ';';
244 }
245 if (attr_diff & bg_mask) {
246 *ptr++ = '4';
247 *ptr++ = color[(attr & bg_mask) >> 4];
248 *ptr++ = ';';
249 }
250 if (ptr != G.attrbuf + 2) {
251 ptr[-1] = 'm';
252 *ptr = '\0';
253 fputs(G.attrbuf, stdout);
254 }
255 }
256 }
257 putchar(CHAR(data));
258 G.col++;
259}
260
261static void screen_dump(void)
262{
263 int linefeed_cnt;
264 int line, col;
265 int linecnt = G.remote.lines - G.y;
266 char *data = G.data + G.current + G.first_line_offset;
267
268 linefeed_cnt = 0;
269 for (line = 0; line < linecnt && line < G.height; line++) {
270 int space_cnt = 0;
271 for (col = 0; col < G.remote.cols; col++, NEXT(data)) {
272 unsigned tty_col = col - G.x; // if will catch col < G.x too
273
274 if (tty_col >= G.width)
275 continue;
276 space_cnt++;
277 if (BW && CHAR(data) == ' ')
278 continue;
279 while (linefeed_cnt != 0) {
280 //bb_putchar('\r'); - tty driver does it for us
281 bb_putchar('\n');
282 linefeed_cnt--;
283 }
284 while (--space_cnt)
285 bb_putchar(' ');
286 screen_char(data);
287 }
288 linefeed_cnt++;
289 }
290}
291
292static void curmove(void)
293{
294 unsigned cx = G.remote.cursor_x - G.x;
295 unsigned cy = G.remote.cursor_y - G.y;
296 int cursor = 1;
297
298 if (cx < G.width && cy < G.height) {
299 gotoxy(cx, cy);
300 cursor = -1;
301 }
302 set_cursor(cursor);
303}
304
305static void create_cdev_if_doesnt_exist(const char* name, dev_t dev)
306{
307 int fd = open(name, O_RDONLY);
308 if (fd != -1)
309 close(fd);
310 else if (errno == ENOENT)
311 mknod(name, S_IFCHR | 0660, dev);
312}
313
314static NOINLINE void start_shell_in_child(const char* tty_name)
315{
316 int pid = xvfork();
317 if (pid == 0) {
318 struct termios termchild;
319 char *shell = getenv("SHELL");
320
321 if (!shell)
322 shell = (char *) DEFAULT_SHELL;
323 signal(SIGHUP, SIG_IGN);
324 // set tty as a controlling tty
325 setsid();
326 // make tty to be input, output, error
327 close(0);
328 xopen(tty_name, O_RDWR); // uses fd 0
329 xdup2(0, 1);
330 xdup2(0, 2);
331 ioctl(0, TIOCSCTTY, 1);
332 tcsetpgrp(0, getpid());
333 tcgetattr(0, &termchild);
334 termchild.c_lflag |= ECHO;
335 termchild.c_oflag |= ONLCR | XTABS;
336 termchild.c_iflag |= ICRNL;
337 termchild.c_iflag &= ~IXOFF;
338 tcsetattr_stdin_TCSANOW(&termchild);
339 execl(shell, shell, "-i", (char *) NULL);
340 bb_simple_perror_msg_and_die(shell);
341 }
342}
343
344int conspy_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
345int conspy_main(int argc UNUSED_PARAM, char **argv)
346{
347 char tty_name[sizeof("/dev/ttyNN")];
348#define keybuf bb_common_bufsiz1
349 struct termios termbuf;
350 unsigned opts;
351 unsigned ttynum;
352 int poll_timeout_ms;
353#if ENABLE_LONG_OPTS
354 static const char getopt_longopts[] ALIGN1 =
355 "viewonly\0" No_argument "v"
356 "createdevice\0" No_argument "c"
357 "session\0" No_argument "s"
358 "nocolors\0" No_argument "n"
359 "dump\0" No_argument "d"
360 "follow\0" No_argument "f"
361 ;
362
363 applet_long_options = getopt_longopts;
364#endif
365 INIT_G();
366 strcpy(G.vcsa_name, "/dev/vcsa");
367
368 opt_complementary = "x+:y+"; // numeric params
369 opts = getopt32(argv, "vcsndfx:y:", &G.x, &G.y);
370 argv += optind;
371 ttynum = 0;
372 if (argv[0]) {
373 ttynum = xatou_range(argv[0], 0, 63);
374 sprintf(G.vcsa_name + sizeof("/dev/vcsa")-1, "%u", ttynum);
375 }
376 sprintf(tty_name, "%s%u", "/dev/tty", ttynum);
377 if (opts & FLAG(c)) {
378 if ((opts & (FLAG(s)|FLAG(v))) != FLAG(v))
379 create_cdev_if_doesnt_exist(tty_name, makedev(4, ttynum));
380 create_cdev_if_doesnt_exist(G.vcsa_name, makedev(7, 128 + ttynum));
381 }
382 if ((opts & FLAG(s)) && ttynum) {
383 start_shell_in_child(tty_name);
384 }
385
386 screen_read_close();
387 if (opts & FLAG(d)) {
388 screen_dump();
389 bb_putchar('\n');
390 return 0;
391 }
392
393 bb_signals(BB_FATAL_SIGS, cleanup);
394
395 // All characters must be passed through to us unaltered
396 G.kbd_fd = xopen(CURRENT_TTY, O_RDONLY);
397 tcgetattr(G.kbd_fd, &G.term_orig);
398 termbuf = G.term_orig;
399 termbuf.c_iflag &= ~(BRKINT|INLCR|ICRNL|IXON|IXOFF|IUCLC|IXANY|IMAXBEL);
400 //termbuf.c_oflag &= ~(OPOST); - no, we still want \n -> \r\n
401 termbuf.c_lflag &= ~(ISIG|ICANON|ECHO);
402 termbuf.c_cc[VMIN] = 1;
403 termbuf.c_cc[VTIME] = 0;
404 tcsetattr(G.kbd_fd, TCSANOW, &termbuf);
405
406 poll_timeout_ms = 250;
407 while (1) {
408 struct pollfd pfd;
409 int bytes_read;
410 int i, j;
411 char *data, *old;
412
413 // in the first loop G.width = G.height = 0: refresh
414 i = G.width;
415 j = G.height;
416 get_terminal_width_height(G.kbd_fd, &G.width, &G.height);
417 if (option_mask32 & FLAG(f)) {
418 int nx = G.remote.cursor_x - G.width + 1;
419 int ny = G.remote.cursor_y - G.height + 1;
420
421 if (G.remote.cursor_x < G.x) {
422 G.x = G.remote.cursor_x;
423 i = 0; // force refresh
424 }
425 if (nx > G.x) {
426 G.x = nx;
427 i = 0; // force refresh
428 }
429 if (G.remote.cursor_y < G.y) {
430 G.y = G.remote.cursor_y;
431 i = 0; // force refresh
432 }
433 if (ny > G.y) {
434 G.y = ny;
435 i = 0; // force refresh
436 }
437 }
438
439 // Scan console data and redraw our tty where needed
440 old = G.data + G.current;
441 G.current = G.size - G.current;
442 data = G.data + G.current;
443 screen_read_close();
444 if (i != G.width || j != G.height) {
445 clrscr();
446 screen_dump();
447 } else {
448 // For each remote line
449 old += G.first_line_offset;
450 data += G.first_line_offset;
451 for (i = G.y; i < G.remote.lines; i++) {
452 char *first = NULL; // first char which needs updating
453 char *last = last; // last char which needs updating
454 unsigned iy = i - G.y;
455
456 if (iy >= G.height)
457 break;
458 for (j = 0; j < G.remote.cols; j++, NEXT(old), NEXT(data)) {
459 unsigned jx = j - G.x; // if will catch j >= G.x too
460
461 if (jx < G.width && DATA(data) != DATA(old)) {
462 last = data;
463 if (!first) {
464 first = data;
465 gotoxy(jx, iy);
466 }
467 }
468 }
469 if (first) {
470 // Rewrite updated data on the local screen
471 for (; first <= last; NEXT(first))
472 screen_char(first);
473 }
474 }
475 }
476 curmove();
477
478 // Wait for local user keypresses
479 fflush_all();
480 pfd.fd = G.kbd_fd;
481 pfd.events = POLLIN;
482 bytes_read = 0;
483 switch (poll(&pfd, 1, poll_timeout_ms)) {
484 char *k;
485 case -1:
486 if (errno != EINTR)
487 cleanup(1);
488 break;
489 case 0:
490 if (++G.nokeys >= 4)
491 G.nokeys = G.escape_count = 0;
492 break;
493 default:
494 // Read the keys pressed
495 k = keybuf + G.key_count;
496 bytes_read = read(G.kbd_fd, k, sizeof(keybuf) - G.key_count);
497 if (bytes_read < 0)
498 cleanup(1);
499
500 // Do exit processing
501 for (i = 0; i < bytes_read; i++) {
502 if (k[i] != '\033')
503 G.escape_count = 0;
504 else if (++G.escape_count >= 3)
505 cleanup(0);
506 }
507 }
508 poll_timeout_ms = 250;
509
510 // Insert all keys pressed into the virtual console's input
511 // buffer. Don't do this if the virtual console is in scan
512 // code mode - giving ASCII characters to a program expecting
513 // scan codes will confuse it.
514 if (!(option_mask32 & FLAG(v)) && G.escape_count == 0) {
515 int handle, result;
516 long kbd_mode;
517
518 G.key_count += bytes_read;
519 handle = xopen(tty_name, O_WRONLY);
520 result = ioctl(handle, KDGKBMODE, &kbd_mode);
521 if (result >= 0) {
522 char *p = keybuf;
523
524 if (kbd_mode != K_XLATE && kbd_mode != K_UNICODE) {
525 G.key_count = 0; // scan code mode
526 }
527 for (; G.key_count != 0; p++, G.key_count--) {
528 result = ioctl(handle, TIOCSTI, p);
529 if (result < 0) {
530 memmove(keybuf, p, G.key_count);
531 break;
532 }
533 // If there is an application on console which reacts
534 // to keypresses, we need to make our first sleep
535 // shorter to quickly redraw whatever it printed there.
536 poll_timeout_ms = 20;
537 }
538 }
539 // Close & re-open tty in case they have
540 // swapped virtual consoles
541 close(handle);
542
543 // We sometimes get spurious IO errors on the TTY
544 // as programs close and re-open it
545 if (result >= 0)
546 G.ioerror_count = 0;
547 else if (errno != EIO || ++G.ioerror_count > 4)
548 cleanup(1);
549 }
550 } /* while (1) */
551}
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